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Biomedical subjects

D N Hogben

Publications and source records attributed to D N Hogben.

6 recordsLinked to original sources

Functional affinity of IgM rheumatoid factor in patients with rheumatoid arthritis and other autoimmune diseases.

The functional affinity of IgM rheumatoid factors (RF) was measured in 31 patients with rheumatoid arthritis (RA), 24 with systemic lupus erythematosus (SLE), 13 with Sjögren's syndrome (SS), and in 13 seropositive healthy individuals. The functional affinity of IgM RF from patients with RA was significantly lower than in the other clinical groups studied. In addition, there was a significant inverse correlation between functional affinity and titre of IgM RF in all the groups. These results suggest that the usual mechanisms of affinity based selective pressure (somatic diversification and antigen selection) may operate differently for autoantibodies to serum antigens such as IgG.

Antibody Affinity↗

The effect of rheumatoid factor on the clearance of endogenous immune complexes formed in low-affinity mice during the induction of immune complex disease.

Intravenous injection of rheumatoid factor (RF) had a marked effect on the clearance kinetics of immune complexes (IC) formed in vivo during induction of chronic immune complex disease in low-affinity mice. RF resulted in a significant increase in IC level and clearance time in 64% of mice with circulating IC after antigen injection, suggesting that RF may alter the handling of potentially pathogenic IC which localize in the renal capillaries causing glomerulonephritis.

Animals↗

HBsAg: anti-HBs immune complexes. A method for separating the constituent components and assessment of the affinity of the antibody.

A number of chemical disruption agents were assessed for their ability to dissociate HBsAg:anti-HBs immune complexes and to release both the antibody and antigen component in immunologically active forms. The most appropriate reagent was 0.1 M diethylamine which could elute up to 81% of anti-HBs antibody bound to solid-phase HBsAg and retained 93% of its antigen-combining activity. Complexes formed at various degrees of antigen excess and pre-exposed to 0.1 M diethylamine at room temperature for 18 h before ultracentrifugation on sucrose density gradients were effectively dissociated. The released antibody and antigen banded at their expected densities. However, the affinity of the isolated antibody for the detergent-solubilized polypeptide complex from purified HBsAg (gp30/p25) and cyclical peptides representing amino acids 124-137 and 139-147 of HBsAg were found to be considerably lower than that of the original pooled anti-HBs immunoglobulin used to form the immune complexes. These results suggest that the highest affinity antibody subpopulation may not be completely dissociated from the complex. Care should thus be exercised in the interpretation of the significance of the observed affinity of the antibody isolated by this and other similar dissociation procedures.

Antibody Affinity↗

Studies on rheumatoid factor: I. The effect of rheumatoid factor on the clearance of preformed immune complexes in mice.

The blood clearance of passively transferred immune complexes (IC), preformed at different antigen-antibody ratios, was measured in mice with LPS-induced rheumatoid factor (RF) and in normal controls. RF had a differential effect on IC clearance, significantly enhancing clearance of complexes formed in antibody excess and slight antigen excess but inhibiting the clearance of complexes formed in moderate (x10) antigen excess. The results are discussed with regard to the mechanisms of IC clearance and suggest that RF may play an important role in governing the behaviour of immune complexes in vivo.

Animals↗

A study of ultrastructural alterations in experimental non-A, non-B hepatitis by electron-beam analysis.

An electron-beam X-ray microanalysis was carried out on sections of liver biopsy specimens obtained from chimpanzees infected with non-A, non-B hepatitis. The microanalysis was concentrated over areas where typical derangement of the endoplasmic reticulum, with the formation of tubular forms possessing walls with electron-dense central membrane, was visualized. These tubular structures are regarded as the most notable pathological alteration in affected hepatocytes. However, the electron-probe microanalysis showed no deviation of the energy spectrum when compared with the background or control analysis.

Animals↗